Apple scab first appears as small, olive-colored lesions on the undersides of the leaves. As the fungus spreads, the top sides of the leaves develop lesions, as well, that may become black or mottled with defined edges. Severely infected trees may become defoliated by mid-summer, making the tree vulnerable to other diseases. The fruit develop black or brown scabs or soft areas.
cytosis. [ 1 sÄ«tÅâ²sis] 2  a condition in which there is a greater than normal number of cells in a tissue or organ.
Not to be confused with Narcosis. Structural changes of cells undergoing necrosis and apoptosis. Necrosis (from the Greek Î½Î­ÎºÏÏÏÎ¹Ï death, the stage of dying, the act of killing from Î½ÎµÎºÏÏÏ dead) is a form of cell injury which results in the premature death of cells in living tissue by autolysis.